Modular automotive seat frame

ABSTRACT

A modular automotive seat frame enabling a variety of seat frames to be fabricated of modular components. The seat back frame includes a pair of side supports each including a cross member which nestingly interfit with one another. The amount of nesting is varied to vary the width of the seat back. An upper member is secured between the side supports and is adapted to support a headrest. In an enhanced embodiment, the seat is an all-belts-to-seat design. A belt retractor is mounted to the nested cross members of the side supports and a shoulder belt terminal is mounted on the upper member of the seat back frame. The terminal permits the height of the shoulder belt loop to be adjusted for comfort and safety.

This is a continuation of Ser. No. 08/240,853, filed May 9, 1994, nowU.S. Pat. No. 5,547,259.

BACKGROUND OF THE INVENTION

The present invention relates to seat frames for automobiles, and moreparticularly to such a frame having an optional "all-belts-to-seat"design.

The physical characteristics of automobile seating and safety beltassemblies are in large part regulated by a set of national safetystandards designed to protect a passenger from injury during collision.When designing seating and restraint systems, reducing cost and weightalso are desirable. In addition, each line of seats must be designed toconform to the size and shape requirements of the particular vehicle.These variations in size and shape typically require a separate framedesign for each seat, which is expensive and time-consuming.

There is a growing trend to provide automotive seating with integralsafety belts. This type of design, commonly referred to asall-belts-to-seat, eliminates the need for separate passenger restraintsystems. Instead, a complete seat and safety belt assembly meetingnational safety standards can be installed together.

One all-belts-to-seat design is disclosed in U.S. Pat. No. 5,253,924,issued Oct. 19, 1993, to Glance. The Glance seat incorporates areinforcing beam added to the seat back frame to support the safety beltshoulder harness above the passenger's shoulder and to transfer crashforces to the frame of the seat. Reinforcing beams add undesired weightto the seat assembly and also create an unattractive asymmetric seatprofile.

Another all-belts-to-seat design is disclosed in U.S. Pat. No.5,123,673, issued Jun. 23, 1992, to Tame. The belt retractors aremounted to an upper portion of the seat back frame. Such a constructionrequires an extremely strong seat back frame that can bear the crashforces imparted by a loaded passenger restraint system.

In addition, current all-belts-to-seat designs include a single-heightsafety belt terminal, which can not be adjusted to match the height ofthe occupant. This reduces the effectiveness of the safety belt and mayeven pose a safety hazard. For example, a terminal location that is toolow may result in potentially injurious downward force being applied toa passenger's shoulder during collision. While a terminal location thatis too high may be uncomfortable or result in unwanted play in the belt.

SUMMARY OF THE INVENTION

The aforementioned problems are overcome by the present inventionwherein a relatively small number of modular components are used tofabricate a wide variety of seat frames for a wide variety of seatshapes, sizes, and aesthetics.

As disclosed, the invention includes a seat back frame having a lowerassembly formed from two L-shaped side supports having nesting crossmembers, an upper member adapted to receive a headrest assembly, and alumbar-support cross member extending between the side supports. Thenesting side supports are fixedly intersecured to define the width ofthe frame. The upper member and the cross member are selected dependingon this width and are fixedly secured to the side supports.Consequently, the basic modular seat back frame has a simple yeteffective construction.

The lower seat assembly also can be fabricated of modular components tosupport seat cushions having a variety of sizes and shapes. Thisassembly incorporates either a pair of nesting "C" shaped members or aset a four "l" shaped members.

In an alternative and enhanced embodiment, the modular seat frame is anall-belts-to-seat design. The retractor for the shoulder belt is mounteddirectly to the nested side members. An adjustable-height, shoulder beltterminal assembly is mounted to, or incorporated into, the upper member.The seat back frame distributes crash forces in a generally verticalcompression pattern throughout the entire seat back frame. Optionally,reinforcing members are installed in the seat back frame to provideadditional strength.

Preferably, the modular side supports are stamped to provide large, flatsurfaces to receive a wide variety of motors and linkages foraccessories such as seat adjusters, lumbar support mechanisms, and beltretractors without the need for custom bracketing.

The present invention allows the manufacture of a wide variety of sizeand shape seats from modular parts without the need for redesign orretooling with each frame. In addition, the present invention providesan all-belts-to-seat design that allows nearly symmetric aesthetics ofthe seating. Further, the adjustable-height shoulder belt terminalassembly allows the on-seat shoulder belt to be adjusted to the heightof the seat occupant.

These and other objects, advantages, and features of the presentinvention will be more fully understood and appreciated by reference tothe detailed description of the preferred embodiment and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the modular seat frame of the presentinvention;

FIG. 2 is a perspective, exploded view of the seat back frame;

FIG. 3 is a perspective view of one of the modular side support;

FIG. 4 is a side elevational view of the modular side support;

FIG. 5 is a top plan view of the modular side support;

FIG. 6 is a back elevational view of the seat back frame;

FIG. 7 is a perspective view of an alternative modular seat frame;

FIG. 8 is a side elevational view of the height-adjustable shoulder beltterminal assembly;

FIG. 9 is a sectional view of the height-adjustable shoulder beltterminal assembly taken along line IX--IX in FIG. 8;

FIG. 10 is a top plan view of the modular seat cushion frame; and

FIG. 11 is a top plan view of an alternative modular seat cushion frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

By way of disclosure and not by way of limitation, an automobile seatframe constructed in accordance with a preferred embodiment of thepresent invention is shown in FIG. 1 and generally designated 10. Theseat frame 10 is mounted on a conventional seat track 120 having aconventional adjuster assembly 122, and includes a lower seat assembly12, a recliner assembly 14, a seat back frame 16, and a headrestassembly 18. For purposes of this disclosure, the terms forward,rearward, upward, and downward will be used to denote typical directionsfrom the reference point of an individual positioned within the seat. Inaddition, the term inward will be used to refer to the direction towardthe center of the area enclosed by the seat back frame 16, and the termoutward will be used to refer to the opposite direction.

The recliner assembly 14 includes upper and lower mounting brackets 14aand 14b that are secured to the lower seat assembly 12 and seat backframe 16, respectively, by conventional means, such as bolts and/orwelding. In the embodiment illustrated in FIG. 1, the lower seatassembly 12 and recliner assembly 14 are conventional elements wellknown to those of ordinary skill in the art. One suitable lower seatassembly is that manufactured and sold by Delta U.S.A. of Monroe, Mich.as a manual adjuster; and one suitable recliner mechanism is thatmanufactured and sold by Atwood Automotive of Battle Creek, Mich. as amanual recliner. While the recliner assembly 14 of FIG. 1 is manuallyoperated, a powered recliner assembly may be substituted therefor.

As perhaps best illustrated in FIG. 2, the seat back frame 16 includes alower assembly 16a, having a pair of side supports 20 and 22, and alumbar support cross member 24. The seat back frame 16 also includes anupper assembly 16b having a headrest tube 26 and a headrest bracket 28.The seat back frame 16 further includes a pair of reinforcing members 30and 32 and an adjustable-height shoulder belt terminal assembly 34.

The two side supports 20 and 22 are near mirror images of each other.The side supports are formed by stamping. The weight and strength of theside supports can be varied relatively easily, for example, by alteringthe gauge of the metal. Each side support 20 and 22 is an elongated,somewhat "L" shaped element that preferably has a generally "U" shapedcross section. This cross sectional profile creates channels 20d and 22din the rear of each side support 20 and 22 that receive the headresttube 26 and reinforcing members 30 and 32 as will be described ingreater detail below. As a further result of this cross sectionalprofile, the side supports 20 and 22 have large, flat walls thatfunction as mounting surfaces for a wide variety of optional elementssuch as a lumbar support assembly, a belt retractor, seat adjustmentmotors, and other seating options.

Referring now to FIGS. 3-5, the side supports 20 and 22 each include anupright member 20a and 22a, a cross member 20b and 22b, and a flangeportion 20c and 22c. Cross member 22b is dimensioned to slidably nestwith cross member 20b. By varying the amount of nesting, or the amountof overlap, between the two cross members 20b and 22b, the width of theseat back frame 16 may be varied. FIG. 3 illustrates side supports 20and 22 nested at an increased width in phantom lines. The nested sidesupports 20 and 22 are fixedly secured to one another, for example bywelding or bolting. A first portion 36 and 38 of each upright member 20aand 22a extends substantially normal to the associated cross member 20band 22b, thereby providing a flat mounting surface for securing the seatback frame 16 to the recliner assembly mounting bracket 14a. A secondportion 40 and 42 of each upright member 20a and 22a extends inwardly atan angle that is acute to the associated cross member 20b and 22b,thereby providing a seat back frame that narrows toward its upperextreme. In a preferred embodiment, each first portion 36 and 38 isapproximately 6 inches in length, the second portion is approximately11.5 inches in length, and the angle of intersection between the twoportions is approximately 13 degrees, 30 minutes. However, it should bereadily apparent that the precise length of each portion 36, 38, 40, and42, as well as the angle of intersection, may be varied as necessary toprovide the desired seat back profile.

The first portion 36 and 38 of each upright member further includescomplex front 36a and 38a and outer 36b and 38b walls designed toprovide controlled collapse of the seat back frame during collision. Asperhaps best illustrated in FIGS. 4 and 5, the outer walls 36b and 38bare somewhat wider than the inner wall 36c and 38c, thereby resulting inslanted front walls 36a and 38a. The slanted front walls 36a and 38a donot lie normal to the direction of typical crash forces and thereforeare not likely to buckle during a typical front end collision. Inaddition, the bends formed between the slanted front walls 36a and 38aand the associated cross members 20b and 22b are formed at an angle tothe plane defined by the outer walls 36b and 38b. This dispositionreduces the likelihood that either of the bends will fold during acollision. As a result of this complex profile, controlled collapse ofthe seat back frame is designed to occur along bends 36d and 38d whichare defined along a plane normal to typical crash forces.

Referring now to FIG. 2, the lower member also includes a lumbar supportcross member 24 that extends between the two side supports 20 and 22 toprovide a mounting surface and strengthen the seat back frame. In crosssection, lumbar support cross member 24 is generally "L" shaped, therebyproviding a pair of perpendicular mounting surfaces 24a and 24b. Crossmember 24 is fixedly secured to side supports 20 and 22, for example, bywelding or bolting.

As perhaps best illustrated in FIGS. 2 and 6, each side support alsoincludes a pair of flanges 20c and 22c that provide additional strengthto the seat back frame. The flanges are stamped as an integral part ofeach side support. However, the flanges may alternatively beprefabricated and welded into place along the side supports.

With reference to FIGS. 1, 2, and 6, the upper member 16b generallyincludes a headrest tube or member 26 and a headrest bracket 28. Theheadrest tube 26 is generally "U" shaped and is manufactured from alength of conventional tubing. The headrest tube 26 includes a crossmember 26c extending between a pair of legs 26a and 26b. The length ofthe cross member 26c will vary from seat to seat as necessary to providea seat back frame 16 of the desired width. The legs 26a and 26b extendaway from one another to allow them to fit within channels 20d and 22dof the side supports. In a preferred embodiment, the outward bend 96 isapproximately 13 degrees, 30 minutes. However, the precise angle of bend96 will vary as necessary to provide the desired profile. The legs 26aand 26b also include a forward bend 98 such that a portion of the uppermember 16b defines a plane extending at an angle to the plane defined bythe lower member 16a. In a preferred embodiment, the angle of bend 98 isapproximately 10 degrees. Again, bend 98 may be adjusted to provide thedesired profile. The headrest tube 26 is preferably formed usingconventional tube bending technology, thereby allowing the production ofvarious size and shape tubes 26 without expensive retooling.

The headrest bracket 28 is welded to the headrest tube 26 as illustratedin FIGS. 1 and 6. In cross section, the headrest bracket 28 ispreferably a generally "C" shaped element having upper and lower flanges28a and 28b that extend downward to give the bracket additionalstrength. A pair of mounting holes 41 are formed through the headresttube 26 and bracket 28 to facilitate the installation of a conventionalheadrest assembly. The bracket 28 and mounting hole 41 configuration maybe varied as necessary to provide the appropriate seating for a varietyof headrest assemblies. The upper member 16b is fixedly secured to thelower member 16a, for example, by welding or bolting.

Referring now to FIG. 7, an optional arm rest assembly 90 may be mountedto the seat back frame 16, along the outer surface of the lower member16a. The arm rest assembly 90 includes a mounting bracket 92 and an armrest 94 that pivots between a storage position (not shown) wherein thearm rest 94 is in alignment with the plane defined by the seat backframe 16, and an operational position (illustrated in FIG. 7) whereinthe arm rest 94 extends substantially perpendicularly from the planedefined by the seat back frame 16.

As illustrated in FIGS. 1 and 7, the seat back frame 16 may also includean optional lumbar support 130. The lumbar support 130 is a conventionalelement available from a variety of well known suppliers. The lumbarsupport 130 may be provided with a conventional manual 132 or powered(not shown) control assembly.

Alternative Embodiments

In an alternative embodiment, the seat frame 10 includes anall-belts-to-seat design. In this embodiment, the modular seat frame 10is fit with a safety belt retractor 42 and an adjustable-height shoulderbelt terminal assembly 34. In addition, the strength of seat back frame16 may bolstered by the installation of reinforcing members 30 and 32.

As perhaps best illustrated in FIG. 7, the belt retractor 42 is mountedto the upper surface of cross member 20b by a single bracket 44 havingan "L" shaped cross section. The bracket 44 is fixedly secured to crossmember 20b, for example, by welding. The retractor 42 is, in turn,bolted or welded to bracket 44. The belt retractor 42 is a conventionalassembly that is commercially available from a variety of well knownsuppliers.

The adjustable-height shoulder belt terminal assembly 34 is designed formodular assembly to the outer surface of the upper member 16b,preferably by welding. Alternatively, the assembly may be structurallyincorporated into the upper member 16b.

The assembly 34 generally includes a housing 46 having top 48, bottom50, front 52, back 54, and side walls 56 and 58. The front wall 52includes a vertical slot 60. In addition, the top 48 and bottom 50 wallseach include a circular opening 62. A jack screw 64 extends through thehousing 46 and is rotatably fitted within the openings 62. The portionof the jack screw 64 enclosed within the housing 46 is threaded. A pairof nuts 66 are seated at opposite ends of the threaded portion 64a toretain the jack screw 64 within the housing 46.

Referring now to FIGS. 7-9, the shoulder belt terminal 70 includes agenerally "H" shaped (in cross section) block member 72, a pair of beltrollers 74 and 76, and a belt loop 78. As perhaps best illustrated inFIG. 9, block member 72 is mounted for vertical movement within slot 60.The block member 72 includes a pair of outer members 72a and 72b thatare interconnected by a cross member 72c that extends through slot 60. Athreaded bore 72d extends through the block member 72 and is threadedlyengaged with jack screw 64. Consequently, rotational movement of thejack screw 64 causes shoulder belt terminal 70 to move vertically withinslot 60.

The belt loop 78 and the rollers 74 and 76 are mounted to the frontsurface 72a of the block member. The rollers 74 and 76 are seated on aconventional bearing or bushing assembly and are skewed to feed a safetybelt 80 from the belt retractor 42 through loop 78 and down in properalignment over the passenger. A conventional manual 140 (See FIG. 7) orpowered (not shown) cable drive system can be mounted to the jack screw64 to allow easy control of the height of the shoulder belt terminal 70.

As shown in FIG. 7, the free end of the safety belt 80 is secured to thelower seat assembly 12 and includes a conventional buckle assembly 82.The buckle assembly 82 locks into engagement with a safety belt socket84 that is also secured to the lower seat assembly 12.

In the all-belts-to-seat embodiment, reinforcing members 30 and 32 arepreferably installed within the lower member 16b to strengthen the seatback frame 16. Reinforcing members 30 and 32 are mirror images of eachother and have a generally "U" shaped cross section that defines achannel 30a and 32a. The reinforcing members 30 and 32 are stamped,brake formed, rolled, or bent to fit within channels 20d and 22d (SeeFIGS. 2 and 6). Preferably, the reinforcing members 30 and 32 aredimensioned so that the headrest tube 26 fits within channels 30a and32a, as shown in FIG. 6.

The reinforcing members 30 and 32 may be customized to contribute to adesired crash pulse. It should be readily apparent that the reinforcingmembers 30 and 32 may be installed to give additional strength to seatback frame 16 regardless of whether or not the all-belts-to-seat designis used.

In a second alternative embodiment, the seat frame 10 is provided with ahigh strength modular seat cushion frame 100 (See FIG. 7). The cushionframe 100 may be configured to allow width adjustment only (See FIG. 10)or both width and depth adjustment (See FIG. 11). The width-onlyadjustable frame 100 includes two "C" shaped members 102 and 104 thatare nested with each other in a manner very similar to side supports 20and 22. The fully adjustable frame 100', however, includes four "L"shaped members 106, 108, 100, and 112 that nest with each other toprovide full adjustment of the seat frame. A frame of diminished widthand depth is shown in FIG. 11 in phantom lines. The members of bothframes 100 and 100' are fixedly secured to one another, for example, bywelding or bolting. Both frames 100 and 100' also include a sloped wall114 and 114' designed to prevent a passenger from "submarining" underthe lap belt during a collision. As shown in the illustrations, thesloped wall 114 and 114' is preferably manufactured as an integral partof frame members 102, 104, 106, and 108.

When a seat track 120 and adjuster assembly 122 of sufficient strengthare used, the seat cushion frame 100 and 100' may be replaced by aninexpensive molded seat pan (not shown).

Upon completion of assembly, the seat frame 10 is cushioned andupholstered as desired. In the all-belts-to-seat embodiment, the beltretractor 42 and adjustable-height shoulder belt assembly 34 are encasedwithin the upholstery.

The above descriptions are those of preferred embodiments of theinvention. Various alterations and changes can be made without departingfrom the spirit and broader aspects of the invention as set forth in theappended claims, which are to be interpreted in accordance with theprinciples of patent law, including the doctrine of equivalents.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A modular automotiveseat back frame, comprising:a first one-piece side support including anintegral cross member; a second one-piece side support including anintegral cross member telescopically received within said cross memberof said first side support; adjustable mounting means for securing saidfirst side support to said second side support at a desired spaced apartdistance by varying a distance said cross member of said second sidesupport is received within said cross member of said first side support;and a headrest tube mounted to said side supports, said headrest tubeinterfitted with said first side support and said second side support.2. The seat back frame of claim 1, wherein each of said side supportsinclude an upright member; andwherein said headrest tube includes afirst end nested within said upright member of said first side supportand a second end nested within said upright member of said second sidesupport.
 3. The seat back frame of claim 1, further comprising anadjustable height shoulder belt terminal assembly.
 4. A modularautomotive seat back frame, comprising:a first side support; a secondside support, each of said side supports including an upright member anda cross member, said cross members dimensioned to slidably nest witheach other; adjustable mounting means for securing said first sidesupport to said second side support at a desired spaced apart distance,said adjustable mounting means including said cross members; a crosssupport extending between said side supports; and an upper membermounted to said side supports, said upper member includes a headresttube mounted to said side supports and a headrest bracket mounted tosaid headrest tube.
 5. The seat back frame of claim 4, furthercomprising at least one high load member mounted to at least one of saidside supports.
 6. The seat back frame of claim 5, wherein said uprightmember of side supports includes a portion contoured to providecontrolled collapse of the seat back during collision.
 7. A modularautomotive seat, comprising:a seat back frame includinga first one-pieceside support including a cross member defining a channel, a secondone-piece side support including a cross member fitted within saidchannel, and an adjustable mounting means for securing said first sidesupport to said second side support at a desired spaced apart distanceby varying a distance said cross member of said second side support isfitted within said channel of said first side support; a lower seatassembly; and an attachment means for attaching said seat back frame tosaid lower seat assembly.
 8. The modular seat of claim 7, furthercomprising a headrest tube having first and second ends; andwherein eachof said side supports include an upright member defining a channel, saidfirst end of said headrest tube fitted within said channel of said firstside support upright and said second end of said headrest tube fittedwithin said channel of said second side support upright.
 9. The modularseat of claim 7, further comprising an adjustable-height shoulder beltterminal assembly.
 10. The modular seat of claim 9, wherein saidadjustable-height shoulder belt terminal assembly includes:a housinghaving a vertical slot; a jack screw extending through said housing; aterminal block threadedly engaged with said jack screw and extendingthrough said slot.
 11. The modular seat of claim 7, wherein said lowerseat assembly includes a modular seat pan.
 12. The modular seat of claim11, wherein said seat pan includes a set of four substantially "L"shaped members mounted together at a desired spaced apart distance, said"L" shaped members capable of nesting with one another at one of a rangeof spaced apart distances whereby seat pans of a variety of widths anddepths may be manufactured from a set of four "L" shaped members havinga single set of dimensions.
 13. A modular automotive seat, comprising:aseat back frame includinga first side support, a second side support,each of said side supports including an upright member and a crossmember, said cross members dimensioned to slidably nest with each other,an adjustable mounting means for securing said first side support tosaid second side support at a desired spaced apart distance, saidadjustable mounting means includes said cross members; and an uppermember having a headrest tube mounted to said side supports and aheadrest bracket mounted to said headrest tube: a lower seat assembly;and an attachment means for attaching said seat back frame to said lowerseat assembly.
 14. The modular seat of claim 13, further comprising atleast one high load member mounted to at least one of said sidesupports.
 15. The modular seat of claim 14, wherein said upright portionof side supports includes a portion contoured to provide controlledcollapse of the seat back during collision.
 16. A modular automotiveseat, comprising:a seat back frame includinga first side support, asecond side support, and an adjustable mounting means for securing saidfirst side support to said second side support at a desired spaced apartdistance; a lower seat assembly including a modular seat pan, said seatpan including two substantially "C" shaped members mounted together at adesired spaced apart distance, said "C" shaped members capable ofnesting with one another at one of a range of spaced apart distanceswhereby seat pans of a variety of widths may be manufactured from a pairof "C" shaped members having a single set of dimensions; and anattachment means for attaching said seat back frame to said lower seatassembly.